Synthesis and characterization of nanocrystalline NaTaO3

Tantalum pentoxide reacts actively with concentrated NaOH solution under hydrothermal conditions at 180 °C. In the reaction between NaOH solution and Ta2O5, the structure and composition of the tantalates depend on the reaction time, and the structure evolution results in a remarkable change in light absorption. Powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and ultraviolet-visible (UV-Vis) diffused reflection spectrum were used to characterize various properties of the obtained solid products. At 180 °C, the reaction proceeds rapidly. With the increase of time, the reflection peaks of unreacted Ta2O5 in the XRD patterns becomes weaker and weaker. Pure NaTaO3 is obtained after 60 min, which is well crystallized with a uniform cubic morphology.